The term "D1" refers to a standard ballpoint pen refill size, which is 67 mm long and approximately 2.3mm in diameter. These refills are inside many compact pens and multi pens.

The team at JetPens has compiled a list of all our ballpoint pens and multi pens that accept D1 refills, which you can view below:

Zebra Minna Mini Ballpoint Pens with Japanese Print

Zebra Penpod Mini Keychain Pens

Zebra Mini T3 Ballpoint Pen

Tombow Pfit Clip Mini Ballpoint Pens

Zebra Sharbo X Multi Pen System

Platinum Double R3 Action Multi Pens

Platinum MWB-1000C 2 Color 0.7 mm Ballpoint Multi Pens

Platinum Double Action R3 Modern Lacquer Ballpoint Multi Pens

Platinum Double Action R3 High Quality Wood 2 Color 0.7 mm Ballpoint Multi Pen + 0.5 mm Pencil

Platinum Double 3 Action Transparent Body 2 Color 0.7 mm Ballpoint Multi Pen + 0.5 mm Pencil

Platinum Double 3 Action Pocket 2 Color 0.7 mm Ballpoint Multi Pen + 0.5 mm Pencil

Platinum Double 3 Action Multi Pens